1
Q
is the basic structural and functional unit of living organisms
A
cell
2
Q
is a collection of ideas and conclusions from many different scientists over time that describes cells and how cells operate
A
cell theory
3
Q
what is the cell theory
A
- all known living things are made up of one or more cells
- all living cells arise from pre-existing cells by division
- the cell is the basic unit of structure and function in all living organisms
4
Q
discovered cell
A
robert hooke, 1665
5
Q
observed living cell
A
anton van leeuwenhoek, 1674
6
Q
discovered nucleus
A
robert brown, 1831
7
Q
discovered fluid content of cell
A
felix dujardin, 1835
8
Q
proposed all plants are made up of cells
A
matthias schleiden, 1838
9
Q
named fluid content cell as protoplasm
A
J.E. Purkinje, 1839
10
Q
proposed all animals are made up of cells
A
theodor schwann, 1839
11
Q
proposed cell is the basic unit of life
A
carl heinrich braun, 1845
12
Q
proposed all cells arise from pre-existing cells
A
rudolf virchow, 1855
13
Q
an organism that is made up of only one cell
A
unicellular organism
14
Q
an organism that is made up of more than one cell
A
multicellular organism
15
Q
- Extremely delicate, thin , elastic, living and semi-permeable membrane
- Made up of two layers of lipid molecules in which protein molecules are floating
- Thickness varies from 75-110 A ̊
- Can be observed under an electron microscope only
A
plasma membrane
16
Q
- Non-living and outermost covering of a cell (plants & bacteria)
- Can be tough, rigid and sometimes flexible
- Made up of cellulose, hemicellulose and pectin
- May be thin or thick, multilayered structure
- Thickness varies from 50-1000 A ̊
A
cell wall
17
Q
- Dense spherical body located near the centre of the cell
- Diameter varies from 10-25 μm
- Present in all the cells except red blood cells and sieve tube cells
- Well developed in plant and animal cells
- Undeveloped in bacteria and blue-green algae (cyanobacteria)
- Most of the cells are uninucleated (having only one nucleus)
- Few types of cells have more than one nucleus (skeletal muscle cells)
A
nucleus
18
Q
Nucleus has a double layered covering called
A
nuclear membrane
19
Q
Colourless dense sap present inside the nucleus known as
A
nucleoplasm
20
Q
Nucleoplasm contains
A
round shaped nucleolus and network of chromatin fibres
21
Q
- are composed of deoxyribonucleic acid (DNA) and protein histone
- condense to form chromosomes during cell division
A
chromatin fibres
22
Q
Chromosomes contain stretches of DNA called
A
genes
23
Q
transfer the hereditary information from one generation to the next
A
Genes
24
Q
- Jelly-like material formed by 80 % of water
- Present between the plasma membrane and the nucleus
- Contains a clear liquid portion called cytosol and various particles
- Particles are proteins, carbohydrates, nucleic acids, lipids and inorganic ions
- Also contains many organelles with distinct structure and function
- Some of these organelles are visible only under an electron microscope
- Granular and dense in animal cells and thin in plant cells
A
cytoplasm
25
* Network of tubular and vesicular structures which are interconnected with one another
* Some parts are connected to the nuclear
membrane, while others are connected to
the cell membrane
* Two types: smooth(lacks ribosomes) and
rough(studded with ribosomes)
Endoplasmic Reticulum
26
* Discovered by Camillo Golgi
* Formed by stacks of 5-8 membranous sacs
* Sacs are usually flattened and are called the cisternae
* Has two ends: cis face situated near the endoplasmic reticulum and trans face situated near the cell membrane
Golgi body
27
* Small, spherical, single membrane sac
* Found throughout the cytoplasm
* Filled with hydrolytic enzymes
* Occur in most animal cells and in few type of plant cells
lysosomes
28
* Single membrane sac filled with liquid
or sap (water, sugar and ions)
* In animal cells, vacuoles are temporary,
small in size and few in number
* In plant cells, vacuoles are large and more in number
* May be contractile or non-contractile
vacuoles
29
* Small, rod shaped organelles bounded by two membranes - inner and outer
* Outer membrane is smooth and encloses the contents of mitochondria
* Inner membrane is folded in the form of shelf like inward projections called cristae
* Inner cavity is filled with matrix which contains many enzymes
* Contain their own DNA which are responsible for many enzymatic actions
mitochondria
30
- are double membrane-bound
organelles found inside plants and
some algae.
- They are responsible for activities related to making and storing food.
- They often contain different types of pigments that can change the colour of the cell.
Plastids
31
- are plastids that produce and store pigments
- They are responsible for different colours found in leaves, fruits, flowers and vegetables
Chromoplasts
32
- are colourless plastids that store foods.
- They are found in storage organs
such as fruits, tubers and seeds
Leucoplasts
33
* is the membrane bound organelle present near the nucleus
* Consists of two structures called centrioles
centrosome
34
* are hollow, cylindrical structures made of microtubules
* are arranged at right angles to each other
centrioles
35
* Formed by microtubules and microfilaments
* Microtubules are hollow tubules made up of protein called tubulin
* Microfilaments are rod shaped thin filaments made up of protein called actin
Cytoskeleton
36
Functions:
- Determine the shape of the cell
- Give structural strength to the cell
- Responsible for cellular movements
Cytoskeleton
37
Functions:
- Form spindle fibres which help in the movement of chromosomes during cell division
- Help in the formation of cilia and flagella
Centrosome
38
Functions:
- Convert light energy into chemical energy in the form of food
- Provide green colour to leaves, stems and vegetables
Chloroplasts
39
Functions:
- Synthesize energy rich compound ATP
- ATP molecules provide energy for the vital activities of living cells
Mitochondria
40
Functions:
- Store various substances including waste products
- Maintain osmotic pressure of the cell
- Store food particles in amoeba cells
- Provide turgidity and rigidity to plant cells
Vacuoles
41
Functions:
- Help in digesting of large molecules
- Protect cell by destroying foreign invaders like bacteria and viruses
- Degradation of worn out organelles
- In dead cells perform autolysis
Lysosomes
42
Functions:
- Modifies, sorts and packs materials synthesized in the cell
- Delivers synthesized materials to various targets inside the cell and outside the cell
- Produces vacuoles and secretory vesicles
- Forms plasma membrane and lysosomes
Golgi body
43
Functions:
- Gives internal support to the cytoplasm
- RER synthesize secretory proteins and membrane proteins
- SER synthesize lipids for cell membrane
- In liver cells SER detoxify drugs & poisons
- In muscle cells SER store calcium ions
Endoplasmic Reticulum
44
Functions:
- Control all the cell activities like metabolism, protein synthesis, growth and cell division
- Nucleolus synthesizes ribonucleic acid (RNA) to constitute ribosomes
- Store hereditary information in genes
Nucleus
45
Functions:
- Provides definite shape, strength & rigidity
- Prevents drying up(desiccation) of cells
- Helps in controlling cell expansion
- Protects cell from external pathogens
Cell wall
46
Functions:
- Maintains shape & size of the cell
- Protects internal contents of the cell
- Regulates entry and exit of substances in and out of the cell
- Maintains homeostasis
Plasma Membrane
